This invention relates in general to a mount for holding a plate-shaped electrical device having a periphery with a multiplicity of electrical contacts. More particularly, this invention relates to a contact assembly, on a mount in the form of a circuit board, for connecting the contacts of the plate-shaped device to respective conductor runs on the circuit board.
In conventional contact assemblies or arrangements of the above-mentioned type, for instance, IC or integrated circuit chips in dual-in-line housings, the IC contacts provided in the peripheral area of the housings are angled off and are either plugged into sockets on the circuit board which are connected to conductor runs, or connected directly thereto by drilling holes in the conductor runs and soldering the angled-off contacts thereto at the holes. While this is a relatively reliable connecting method, it is very expensive since the conductor runs must be provided with corresponding holes and the contacts must be threaded into these holes before the soldering can take place. Moreover, the so-called dual-in-line housings already contain film sections in which IC-chips are held and electrically contacted; in such housings the electrical contact points on the film section must be brought to the outside and connected to the contacts in the peripheral areas of the housing. In addition to the expensive fastening, this arrangement requires a relatively large amount of space on the circuit board.
During assembly, the film sections are brought by hand into the necessary position coinciding with the contacts and are held there, while the now oppositely arranged peripheral contacts of the film section, provided with solder, are soldered to the mating contacts on the conductor runs, likewise provided with solder. In this manual operation, extreme care must be taken to ensure that accurate positioning is obtained. In addition, the soldering operation, which is difficult because of the smallness of the film sections, places stringent requirements on the person doing the soldering. The entire process requires considerable time because of the necessary precision. Since the success of the manual mounting operation depends on the qualifications and disposition of the person doing the positioning and soldering, errors in soldering or even partial destruction of the IC chip-bearing film sections, which must be soldered sequentially in a production run, are to be expected. A disproportionately large rejection rate frequently occurs.
It is furthermore possible to use window masks for positioning the film sections carrying the IC chips, the windows being designed and arranged so that the film sections occupy the specified positions upon a manual insertion into the windows. The disadvantages of manual mounting, including the large amounts of time required and the high rejection risk, still remain, however. In addition, a mask makes the holding and the soldering of a film section more difficult.
It is therefore an object of the invention to provide an improved contact arrangement of the above-mentioned type, which can be used particularly with relatively small electronic circuit boards and by which the connection of contacts and conductor runs can be made faster, more simply and more reliably.